United States

Environmental Protection Agency

Pollution Prevention and

Toxics (7407)

Winter 1999

EPA 747-N-99-001

News and Information

Chemicals in Our Community

Our Approach to

Endocrine Disruptors

Lynn R. Goldman, M.D.

Dr. Goldman served as Assistant Administrator of the Office of Prevention, Pesticides

and Toxic Substances from the Spring of 1993, and chaired the Endocrine Disruptor

Screening and Testing Advisory Committee. She left the Agency on December 31, 1998.

Recently, increased scientific and public attention has focused on the potential

effects of synthetic chemicals on the hormone, or endocrine, systems of humans and

wildlife. The endocrine system consists of the glands and the hormones they produce

that help guide the development, growth, reproduction and behavior of humans and

animals. Concerns are about potential health effects, like cancers and developmental

toxicity, as well as adverse effects on species in the environment. Since we do not

know enough about the complex interactions of chemicals and hormone systems,

EPA’s first efforts in dealing with the emerging issue of environmental endocrine

disruptors were in the area of research.

EPA has been a leader within the federal government in developing the science

related to endocrine disruption. EPA held two workshops in 1995 to determine what

research was needed to respond to human health and ecological questions associated

with endocrine disruptors. EPA initiated the following actions identified from the

workshops:

(1) In 1996, established a research program on endocrine disruptors that grew to $14

million per year, $8 million of which is dedicated to research in academic laboratories;

(2) Assessed the scientific literature related to endocrine disruptors and published a

report entitled, Special Report on Environmental Endocrine Disruption: An

Effects Assessment and Analysis in 1997;

(continued on page 2)

IN THIS ISSUE:

■ Endocrine Disruptors

■ PBTs
2 Chemicals in Our Community

(3) Chaired an interagency committee to

develop an inventory of federal research on

endocrine disruptors; and

(4) Funded a National Research Council study

on the science of endocrine disruption.

Fourteen federal agencies participated in the

development of the inventory, which will be used

to coordinate research efforts and identify issues

that are not funded. The U.S. inventory has

become the model for an international inventory

to coordinate research among other countries.

In August 1996, the Congress concluded that

research was not enough. Concerned by the

unexplained rise in breast cancer and other

diseases that seem to be related to the endocrine

system, Congress included a requirement in the

Food Quality Protection Act (FQPA) that EPA

screen pesticides for estrogenic effects on the

female reproductive system that may contribute

to disease. Just a few days after the passage of

the FQPA, Congress passed amendments to the

Safe Drinking Water Act which contained similar

provisions to screen drinking water sources for

estrogenic endocrine disrupting chemicals. Both

bills also authorized EPA to test for other

endocrine effects.

Faced with the challenge of developing a

screening program in an area where so many

questions were still unanswered by scientific

research, and with the hope that a consensus

would speed acceptance and implementation by

industry, I thought that a consensus-based

approach, while difficult, would be the best way

to proceed. The Agency appointed an advisory

committee to assist in determining how to set

priorities for substances, what short term

screening and analytical tools the Agency should

use, and what tests could be employed to enable

the Agency to fully assess the hazard of

suspected endocrine disruptors.

We tested the breadth of support for this

approach by convening a meeting with our major

stakeholders on May 15, 1996. All stakeholders

endorsed forming an advisory committee and on

October 16, 1996, the Endocrine Disruptor

Screening and Testing Advisory Committee,

better known as EDSTAC, was formed.

EDSTAC was composed of 39 members

representing the pesticide and commercial

chemical industries, small businesses, state

(continued from first page)

Chemicals in Our Community is published

by EPA’s Office of Pollution Prevention &

Toxics (OPPT) to increase public awareness

of and access to news and information on

toxic chemicals and pollution prevention

available through OPPT. This resource is

also available on the Internet at: http://

www.epa.gov/opptintr/opptpub.htm.

Mailing address:

Chemicals in Our Community

US EPA (7407)

Office of Pollution Prevention & Toxics

401 M Street, SW

Washington, DC 20460

Advisory Board:

IAB Project Manager:

Georgianne McDonald

EAD Project Manager: Mary Wigginton

Publisher: Marla Hendriksson

Senior Editors: Georgianne McDonald,

Diane Sheridan, and Mary Wigginton

OPPT Divisional Representatives:

Dan Fort (EETD), Odelia Funke (IMD),

Patricia Grim (OPME), Leonard Kiefer (RAD),

Chris Tirpak (CCD), and Chen Wen (PPD).

Faced with the

challenge of

developing a

screening

program ...

I thought that

a consensusbased

approach,

while difficult,

would be the

best way to

proceed.

(continued on page 4)

In This Issue

Our Approach to

Endocrine Disruptors ..................1

The Endocrine Disruptor Story ...3

Sorting and Priority Setting.........5

Screening and Testing ...............7

EPA’s Strategy for Priority

Persistent, Bioaccumulative,

and Toxic (PBT) Pollutants ..........9

Reducing PBT Chemicals

in Waste .....................................10

How EPA is Reviewing

New PBT Chemical Substances 11

Progress of the Great Lakes

Binational Toxics Strategy ........13

Update on EPA’s Fish

Contamination Program ..........14

EPA’s Draft Action Plan

for Mercury................................16

Preparing the Mercury

Research Strategy ....................17
Winter 1999 3

Small

disturbances in

endocrine

function,

particularly

during certain

highly sensitive

stages of the

life cycle (e.g.,

development,

pregnancy,

and lactation),

can lead to

profound and

lasting effects.

The Endocrine Disruptor Story

Gary Timm

The endocrine system is a chemical

communication system that coordinates and

regulates the processes that make the life of a

multicellular organism possible. An endocrine

system is essential to the life of multicellular

animals and is found in all mammals, birds, fish

and invertebrates. Hormones are produced by

various glands and travel through the blood to

receptors which are located in various tissues

throughout the body. Hormones are biologically

very potent molecules, and are therefore

effective at small concentrations (e.g., parts per

trillion). Much like a lock and key, hormones act

by binding to receptors that are produced within

cells. The hormone-receptor complex switches

on or switches off specific biological processes

in cells. The receptors are quite specific for the

appropriate hormone but they can interact with

molecules that are similar to the natural

hormone. Over 50 hormones have been

identified in humans and other vertebrates.

Examples of biological processes controlled by

hormones include sexual differentiation, growth

and function of reproductive organs (testosterone

and estradiol); control of blood sugar (insulin);

and body growth and energy production (growth

hormone and thyroid hormone).

The evidence of endocrine disruption is

substantially stronger for fish and wildlife than

for humans. A series of field and laboratory

investigations with marine snails demonstrates

that compounds like tributyltin, which are used

in antifouling paints on ships, can have

significant hormonal effects on some snail

species at concentrations 1,000 times lower than

lethal exposure concentrations. These

compounds can irreversibly induce male sex

characteristics on females (masculinization)

which can lead to sterility or reduced

reproduction. Field investigations in many parts

of the world suggest this class of compounds

may be responsible for localized reductions in

specific snail populations. Feminized males and

hermaphroditic fish (fish having reproduction

organs of both sexes) have been observed in

rivers below sewage treatment plants. Scientists

suspect that natural human estrogens, synthetic

estrogens in birth control pills, and substances

used in the manufacture of certain detergents are

involved. Researchers have documented

masculinization, altered sexual development and

decreased fertility for some fish species near

pulp and paper plant discharges. In many cases

specific causative agents have not been

identified. However, correlative data supported

by laboratory studies in many cases suggest that

compounds such as alkyl phenol ethoxylates,

their degradation products, chlorinated

dibenzodioxins and difurans, and polychlorinated

biphenyls (PCBs) could be the causative agents.

One of the most fully documented examples

of ecological effects caused by disruption of

endocrine function was reported for alligators in

Lake Apopka, Florida. Detailed field and

laboratory investigations revealed that a mixture

of pesticides (dicolfol, DDT, and its breakdown

product, DDE) associated with a spill in 1980 was

responsible for a variety of developmental effects

that indicate a demasculinization of male

alligators and “super-feminization” of females.

The effects of the spill also included detrimental

effects on hatching success and population levels.

Some research shows instances of effects on

mammals and birds. A variety of organochlorine

insecticides have been implicated in eliciting

feminization of male gull embryos, suggesting

that these effects may be contributing to

population declines and skewed sex ratios in

Western gulls in California and herring gulls in

the Great Lakes. Although the extreme

sensitivity of mink, seals, and related species to

adverse reproductive effects from exposure to

some dioxins and PCBs is well known, and

controlled laboratory studies demonstrate similar

effects on rodents, research has not established a

(continued on next page)

Endocrine Disruptors
4 Chemicals in Our Community

link between exposure to endocrine disruptors

and population declines for wild mammalian

populations.

Reports show that humans exposed to

relatively high concentrations of certain

contaminants suffered adverse effects. However,

whether such effects are occurring in the human

population from exposure to concentrations

present in the surrounding environment, drinking

water, and food remains unclear. Several

conflicting reports have been published

concerning declines in the quality and quantity of

sperm production in humans over the last four

decades, and there are reported increases in

certain cancers in highly sex-hormone sensitive

tissues (e.g., breast, prostate, testes). Such effects

may have an endocrine-related basis, which has

led to speculation about the possibility that these

endocrine effects may have environmental causes.

However, considerable scientific uncertainty

remains regarding the actual causes of such effects.

Nevertheless, there is little doubt that small

disturbances in endocrine function, particularly

during certain highly sensitive stages of the life

cycle (e.g., development, pregnancy, and

lactation), can lead to profound and lasting effects.

The body of scientific research on human

epidemiology, laboratory animals, and fish and

wildlife provides a plausible scientific hypothesis

that environmental contaminants can disrupt the

endocrine system, leading to adverse health

consequences. A critical issue is whether

surrounding environmental levels are sufficiently

high to exert adverse effects on the general

population. To answer this question we must

understand whether or not there is a threshold

dose, that is, a dose below which exposure is

safe, or whether exposure to any level of some

endocrine disruptors carries a risk. Government

agencies, industry, and academia are currently

conducting various types of scientific studies

(epidemiology, mammalian toxicology, and

ecological toxicology) to resolve many of the

scientific questions and uncertainty surrounding

the endocrine disruptor issue. Within a few years

we hope to have a much better understanding of

the nature and breadth of this problem.

(continued from previous page)

governments, Federal agencies, public health and

environmental groups, and experts from

academia. It was truly inclusive. EDSTAC held

nine meetings from October 1996 until July

1998. These meetings were open to the public

and held in major cities across the country to

enable citizens to listen to the debate and offer

comments to the Committee.

EDSTAC formed four workgroups to deal

with the voluminous issues associated with

endocrine disruptors and reported their

recommendations back to the main committee.

They were the Principles Workgroup, the

Priority Setting Workgroup, the Screening and

Testing Workgroup, and the Communications

and Outreach Workgroup. EDSTAC submitted

its final report in August l998 enabling EPA to

meet the deadline specified in the FQPA for

developing a screening program. The EDSTAC

Final Report contained 71 consensus

recommendations to EPA and detailed a stepwise approach to screening chemicals that

begins with sorting, and proceeds to priority

setting, screening, and finally testing. Our

Science Advisory Board and the Federal

Insecticide, Fungicide, and Rodenticide Act

(FIFRA) Science Advisory Panel consultants

peer reviewed it in May l998; they will conduct

a final review in early 1999. Testing is

recommended on substances that possess

endocrine disrupting properties identified

during the screening phase. EPA has now

adopted the EDSTAC’s recommendations as the

basis for its endocrine disruptor screening

program and requested public comment on the

proposal in the December 28, 1998 Federal

Register. We have also published a draft

implementation plan for notice and comment.

I want to once again express my gratitude to

individuals who served on EDSTAC and its

workgroups and gave so generously of their time

and talent in helping EPA accomplish its mission

of protecting the health of the American people

and our environment. Chairing EDSTAC was

one of the most rewarding experiences of my

career at EPA.

Our Approach

(continued from page 2)
Winter 1999 5

Sorting and Priority Setting

Gary Timm

EPA formed the Endocrine Disruptor

Screening and Testing Advisory Committee

(EDSTAC) to help the Agency determine

testing needs for endocrine disruptors.

EDSTAC was asked to recommend which

chemicals should be screened for endocrine

disruption effects, and how to set priorities for

reviewing these chemicals.

EDSTAC recommended that EPA consider

87,000 chemicals as potential candidates for

screening. This huge number of chemicals

includes over 600 active pesticide ingredients,

1800 pesticide inert ingredients (chemicals

having little or no ability to react), over 75,000

chemicals in U.S. commerce, covered under the

Toxic Substance Control Act (TSCA), and

thousands of other chemicals including food

additives, cosmetics, natural compounds in

nutritional supplements, and drinking water

contaminants. Although EPA has no jurisdiction

over food additives, cosmetics, and nutritional

supplements, EPA did commit to work with other

agencies to test chemicals that fall outside EPA’s

jurisdiction. Because EPA cannot screen so many

chemicals at one time, the Agency will prioritize

and screen the results in batches and phases.

The first task is to develop a database to

handle all of the data required for priority setting.

The database will allow EPA to extract existing

information (production volume, uses,

monitoring data, physical and chemical

properties, toxicity, etc.) from various sources

and use it to sort and rank chemicals.

To winnow the number of chemicals from

the 87,000, EPA will sort chemicals into four

categories. These categories consist of the

following:

■ Category 1, known as the Hold Category,

consists of compounds that are too big to

penetrate the skin or other membranes —

that is, polymers. Polymers are compounds

of high molecular weight derived from the

addition of many smaller molecules, or from

the condensation of many smaller molecules

when water, alcohol, or the like, is

eliminated. Also included in this category

are certain known non-toxic substances such

as inert pesticides.

■ Category 2 consists of the chemicals

needing screening level data to determine

whether or not they have the potential to

interact with the endocrine system.

■ Category 3 consists of substances known

to have the potential to interact with the

endocrine system, that is, those substances

having data equivalent to some or all of Tier

1, but in need of data for hazard assessment.

(For a description of Tier 1, see article,

“How EPA is Reviewing New PBT

Chemical Substances.”) EPA plans to use

available information, High Throughput PreScreening Steps (HTPS) data, and the

Endocrine Disruptor Priority Setting Data

Base to establish Tier 1 screening priorities.

EPA anticipates, however, that the quantity

and quality of exposure and effects

information will be uneven for the majority

of chemicals.

■ Category 4 consists of substances having

complete test data that are ready for hazard

assessment, risk assessment and possibly

risk management.

(continued on next page)

Endocrine Disruptors
6 Chemicals in Our Community

EDSTAC considered several different

priority setting approaches to determine in what

phase a chemical would be screened. In all of the

priority setting approaches examined, EDSTAC

considered both exposure and effects. The

Committee rejected the approaches combining

exposure and effects to give a ranking, because it

felt that such an approach would cause EPA to

focus on chemicals where there is little

information. Chemicals having the least amount

of information should be placed at a lower

priority. The EDSTAC approach recommended

that EPA group chemicals together based on like

information, or information chemicals have in

common, such as high production volume

chemicals, chemicals found in drinking water, or

chemicals that are released to the environment.

This approach avoids “apples to oranges”

comparisons, because the information used to

group chemicals is the same information that is

used to establish their ranking. EDSTAC called

these groups of chemicals “compartments.” A

chemical can obviously fall into more than one

compartment. After chemicals are sorted into

compartments, they should be ranked for

attention.

Unfortunately, EDSTAC’s priority-setting

efforts were incomplete due to the number of

chemicals to be addressed in a short period of

time. EDSTAC defined some compartments in

its recommendations to EPA, but most have yet

to be defined. Examples of compartments,

include high production volume chemicals,

chemicals in consumer products, chemicals

found in biological tissue, pesticide active

ingredients, formulation ingredients in

pesticides, and chemicals found in sources of

drinking water. EDSTAC specified that special

compartments be established for mixtures,

naturally occurring non-steroidal estrogens

(estrogenic substances produced by plants such

as soybeans), and public nominations. EDSTAC

felt that nominations from private citizens would

focus attention on chemical exposures at the

community level rather than the national level.

EPA accepted EDSTAC’s recommended

compartment-based approach, and EDSTAC’s

recommendation to continue EPA’s involvement

with the public. EPA has not attempted further

specification of the compartments.

To further develop the list of priority setting

compartments, EPA plans to convene a multistakeholder technical workshop in January.

Based on public feedback, and comments

received on EPA’s proposed policy statement,

EPA will establish a limited number of

compartments. EPA will sort chemicals into

these compartments using existing information,

and the criteria that define each compartment.

EPA will then rank chemicals within the

compartments according to criteria related to

those for inclusion in the compartment. Finally,

the highest priority chemicals in each

compartment will form the group of chemicals

going into the first phase of the screening

program. One advantage of the phased approach

is the ability to apply what is learned during the

first phase to subsequent phases. Thus, EPA will

reevaluate the screening program and make

appropriate adjustments at the end of each phase.

This process will introduce the flexibility to

apply what is learned from both the screening

program and ongoing research. In this way, EPA

hopes to guarantee a cohesive and consistent

long-term program for endocrine disruptors.

(continued from previous page)

EDSTAC

recommended

that EPA

consider 87,000

chemicals

as potential

candidates

for screening.
Winter 1999 7

Screening and Testing

Gary Timm

Commencing in 1995 and continuing into

1997, a series of workshops was held in the U.S.

and overseas. The purpose was to identify short

term laboratory analytical methods or assays that

could be used to screen chemicals for their

potential to disrupt the endocrine system of

humans, fish and wildlife. One of the workshops,

the mammalian workshop, looked at over 50

such assays. Some assays were in vitro

(conducted with cell cultures in glassware)

others were in vivo procedures (using live

animals). Scientists evaluated each assay based

on its:

• validity — Does it measure what it is

supposed to?

• reliability — Can you get the same results

from lab to lab and from time to time?

• sensitivity — Can it measure active

compounds that have weak effects or only

strong ones?

• suitability as a screen — Is it cost-effective

and quick and easy to perform?

A consensus of the workshop participants

concluded that no single assay is effective for

use as a screen. A battery of assays is needed.

Participants also agreed that the battery of assays

should be composed of both in vitro and in vivo

procedures. The advantages of the in vitro

procedures are increased sensitivity, lower cost

and shorter time frames. A disadvantage is that

in vitro tests do not provide feedback about the

workings of the endocrine system and provide

only limited information on an animal’s ability to

metabolize or transform chemicals.

The Endocrine Disruptor Screening and

Testing Advisory Committee (EDSTAC) built

upon the efforts of these workshops and

constructed a battery of Tier 1 screens to identify

the potential of chemicals to interact with the

endocrine system, and a battery of Tier 2 tests to

generate the kind of data EPA needs for hazard

assessment. EPA is proposing to accept

EDSTAC’s recommendations for screening and

testing (Federal Register, December 28, l998)

for effects on three hormone systems —

estrogen, androgen, and thyroid — and will

invite public comment on this approach.

Tier 1 would consist of three in vitro assays

and five in vivo assays. To minimize the chances

of missing an endocrine-active chemical, each of

the three hormone systems is covered by at least

two assays in the battery. The first two in vitro

assays detect binding to the estrogen and

androgen receptors. These assays can run

automatically. EDSTAC therefore recommended

that EPA conduct the automatic assays on 15,000

chemicals so that the Agency could use the

results to set priorities for the remaining

chemicals in Tier 1. EPA could run the rest of

Tier l on a smaller set of chemicals, at a

minimum, because it would take far longer to run

the full Tier 1 battery (eight assays) on so many

chemicals. EPA expects substantially fewer

chemicals than 15,000 would go through the full

Tier 1 screen. The third in vitro assay in Tier 1

(steroidogenesis) detects the potential of the test

substance to interfere with the enzymes that are

responsible for making the steroid hormones,

i.e., the two sex hormones and others that are

derived from cholesterol. If the body cannot

synthesize these hormones in adequate amounts,

or makes too much, serious developmental

consequences can result.

Of the five in vivo screens, one is a

relatively short-term assay in females that

(continued on next page)

Endocrine Disruptors

EPA is proposing

to accept

EDSTAC’s

recommendations

for screening

and testing for

effects on

three hormone

systems —

estrogen,

androgen, and

thyroid — and

will invite public

comment on

this approach.
8 Chemicals in Our Community

measures estrogenicity (the uterotrophic assay).

Another is a short-term assay in males that

measures androgenicity (the Hershberger assay).

The most complex assay is a 20-day assay in

immature females that follows them through

puberty to detect potential estrogenic effects and

thyroid effects. The frog metamorphosis assay

also detects thyroid effects since tail resorption

depends on adequate amounts of the thyroid

hormone. Fish are included in the screening

battery because they are the oldest class of

vertebrates and are the farthest removed from

mammals.

EPA is quite confident that chemicals that

test negative in the Tier 1 screening battery are

not likely to interact with the estrogen, androgen,

or thyroid systems. Therefore, chemicals that test

negative in Tier 1 would not be tested in Tier 2.

Chemicals testing positive in Tier 1, however,

will generally be required to be tested in all Tier

2 tests. Tier 2 will contain representatives of all

major types of animals. It will include testing for

reproductive effects in mammals, fish, birds,

amphibians, and invertebrates. The Agency will

use data from the mammalian reproductive study

to assess the risk to humans and to mammals that

live in the wild. Data from the other tests will be

used to assess the risk to fish, birds, and

invertebrates.

(continued from previous page)

Screening and Testing
Winter 1999 9

EPA has developed a draft strategy to further

reduce risks from persistent, bioaccumulative,

and toxic (PBT) pollutants. These PBT pollutants

are highly toxic, long-lasting substances that

build up in the food chain to levels that are

harmful to health in humans and the ecosystem.

Health warnings about eating fish due to PBTs in

the U.S. increased by 80% in four years, from

1,278 in 1993 to 2,299 in 1997, primarily

because states are doing a better job of

monitoring and setting protective levels. PBTs

are associated with a range of adverse human

health effects, including effects on the nervous

system, reproduction, and fetal and child

development. PBTs have also been linked to

cancer and genetic impacts. EPA is especially

interested in protecting children and women of

childbearing years, and in restoring the valuable

quality of our nation’s waterways. EPA’s

challenge in reducing risks from PBTs stems

from their ability to travel long distances, to

transfer easily among air, water, and land, and to

linger for generations.

The first main element of EPA’s strategy is

to develop and implement national action plans

that reduce risks from select PBTs. These plans

will use all of EPA’s tools, across all media.

EPA’s first national action plans will be

developed for the 12 priority PBTs named in the

Canada-U.S. Binational Toxics Strategy. EPA has

already developed a draft action plan for mercury

(see article in this issue), and will be developing

plans for the remaining 11 substances named in

the Binational Toxics Strategy — aldrin-dieldrin,

benzo(a)pyrene, chlordane, DDT (+DDD+DDE),

mirex, hexachlorobenzene, alkyl-lead,

octachlorostyrene, PCBs, dioxins and furans, and

toxaphene.

EPA’s Strategy for Priority Persistent,

Bioaccumulative, and Toxic (PBT) Pollutants

Kathy Davey

The second element of the strategy is to

select more priority PBTs for future national

action plans. The third element is to stop the

flow of new PBTs into commerce. The fourth

and final element of the strategy is to develop

improved right-to-know measures of progress for

the public, so people can tell whether we are

achieving our national goals and commitments.

To date, EPA actions to reduce risks from

PBTs have largely consisted of individual EPA

offices each using their separate authorities to

control PBTs in one media (air, water, land) at a

time. What is new in EPA’s PBT strategy is a truly

multi-media approach. Since these substances

move among air, water, and land, we need to use

all available tools — voluntary, regulatory,

enforcement and compliance, research, and

international — in combination with each other to

break the cycle of transferring pollutants from one

place to another. As an example, once state-based

voluntary efforts retire more mercury from

circulation and use, a national approach is needed

for what to do with the mercury. Re-using

mercury commercially is not a viable answer.

States will also need national help to address the

mercury blowing in from other countries.

Near-term actions under the PBT Strategy

are underway to prevent the introduction of new

PBTs in commerce, encourage voluntary

reduction of PBTs in hazardous waste, increase

the public’s right-to-know about local sources of

PBT emissions and mercury emissions from

utilities, and evaluate fish in U.S. water bodies

for PBT contamination.

EPA cannot do this alone. We will work

closely with our regulatory partners and engage

in partnerships with industry, environmental

groups, and the public to get the PBT job done.

EPA is

especially

interested in

protecting

children and

women of

childbearing

years, and in

restoring the

valuable

quality of our

nation’s

waterways.

PBTs
10 Chemicals in Our Community

Reducing PBT Chemicals in Waste

Douglas Heimlich

On November 9, 1998, EPA published in the

Federal Register a Notice of Data Availability on

the Draft RCRA Waste Minimization PBT

Chemical List. The list contains 53 chemicals

which will be the focus of source reduction and

recycling activities aimed at reducing persistent,

bioaccumulative, and toxic (PBT) chemicals

present in hazardous waste. Comments on the

Notice are due on February 16, 1999.

The List, also known as the RCRA PBT

List, includes certain PBT chemicals that may be

present in some industrial hazardous wastes

regulated under the Resource Conservation and

Recovery Act (RCRA). PBT chemicals do not

readily break down or decrease in potency after

they are released to the environment. Over time,

these chemicals are likely to accumulate in soils

or other environmental media, be absorbed or

ingested by plants and animals, accumulate in

animal and plant tissue, pass through the food

chain, and potentially cause long-term human

health or ecological problems (such as cancer

and birth defects in humans, or reduced

ecological populations). PBT chemicals are

internationally recognized as a global

environmental concern.

The Agency aims to use the List to raise

government, industry, and public awareness of

the potential effects of these chemicals in the

environment, and focus coordinated public and

private actions to reduce the generation of these

chemicals in hazardous waste by 50 percent by

the year 2005. The emphasis will be on source

reduction and recycling activities to get the job

done. The 50/2005 goal was established in the

Waste Minimization National Plan, which EPA

developed with extensive input from states,

industry, environmental groups, and private

citizens. The Plan also aims to avoid transferring

these PBT chemicals from one environmental

form to another (e.g., from air to water).

The List can be a valuable resource for state

and local governments, citizen organizations, and

individuals to promote reductions in the amount

and toxicity of PBT chemicals contained in

hazardous wastes. EPA also plans to use the List

in working with states, industry, environmental

groups and other stakeholders to identify a

variety of implementation approaches for

promoting progress toward the 2005 goal. The

List will be promoted in workshops, technical

assistance, progress reporting, developing

partnership agreements, regulatory reinvention

projects, and other venues.

The Draft RCRA PBT List is an important

component of the Agency’s PBT Strategy,

which integrates all of EPA’s activities focusing

on priority PBT chemicals and aims to measure

collective Agency progress on reducing uses

and releases of PBTs nationally.

PBTs
Winter 1999 11

How EPA is Reviewing

New PBT Chemical Substances

Ken Moss

PBT chemical substances possess

characteristics of persistence (P) in the

environment, accumulation in biological

organisms (bioaccumulation (B)), and toxicity

(T) that make them priority pollutants because of

their potential risks to humans and ecosystems.

EPA developed a category of PBT chemical

substances by defining what it means for a

chemical to be persistent, bioaccumulative, and

toxic. The category statement includes the

boundary conditions that would determine

inclusion in (or exclusion from) the category, and

standard toxicity and environmental fate tests to

determine if a chemical fits within those

boundaries.

Chemical substances characterized as

suspected persistent bioaccumulators may need

to undergo testing on “P” and “B” endpoints

which, if confirmed, would be followed by

appropriate toxicity testing to classify “PBT

chemical substances.” Establishment of this

category helps the Agency gauge the flow of

PBT chemical substances through the New

Chemicals Program and measures the results of

its risk screening and risk management work.

Defining a PBT category helps EPA to

gather additional information as needed about

persistence and bioaccumulation and tailor

regulatory requirements as appropriate to protect

human health and the environment. Depending

upon the level of certainty for the PBT properties

of a new chemical (e.g., measured vs. estimated

values), the magnitude of Agency concerns, and

conditions of expected use and release of the

chemical, control action by EPA may be needed

in varying degrees, up to a total ban on

production of the chemical.

The criteria for banning a chemical from

being produced are equivalent to those that have

been used internationally to eliminate from

commerce new chemicals that are known PBT

substances, chemicals like the polychlorinated

biphenyls (PCBs) and the pesticide DDT. For

new chemical substances meeting these criteria,

EPA’s concern is higher than for other PBTs and

the Agency looks carefully at any and all

environmental releases. Because of the increased

concern, more stringent control action would be

a likely outcome, including a ban on commercial

production, until data are submitted which allow

the Agency to determine whether the level of risk

can be appropriately addressed by less restrictive

measures.

With specified controls,

EPA might allow a new

chemical categorized as a

PBT to enter the market. For

example, EPA might allow a

Premanufacture Notice

(PMN) submitter (anyone

wanting to manufacture a

“new” chemical) to

commercialize a substance

upon signing a negotiated and

legally binding consent

agreement. Stipulated in the

agreement could be annual

reporting requirements on

environmental releases of the

PMN substance and specific

limits on exposures, releases

or uses while test data are being developed.

In many cases, the PBT status of the new

chemical is ambiguous and testing is needed.

EPA has developed a testing strategy for this

category of new chemical substances which

describes test data that EPA believes are needed

to evaluate the potential persistence,

bioaccumulation, and toxicity of a PBT chemical

substance. The tests are tiered. Depending upon

the circumstances, such as magnitude of

environmental releases, results of testing already

conducted, or what we know about other

chemicals with similar chemical structures (an

approach called Structure Activity Relationships

or SARs), EPA will require additional testing in

order to screen the chemical.

PBTs

(continued on next page)
12 Chemicals in Our Community

■ Tier 1. If, based upon SAR and professional

judgment, EPA scientists identify a new

chemical as a possible PBT chemical, the

chemical manufacturer first needs to

conduct simple tests to measure its tendency

to partition towards either water or fish

tissue (scientifically described as biological

lipids or fat) and its ability to readily

degrade in the environment. Once the

chemical is dissolved in water, the organic

solvent octanol (thought to have properties

that mimic body fat) is then placed in the

test vessel and the entire two-phase (water

phase and organic phase) system is shaken

to mix everything up. After everything

settles, the amount of the test chemical is

measured in both the water and the octanol

phase. The ratio of the amount in the octanol

phase over that in the water phase is called

the octanol-water partition coefficient, or

Kow. The lower the Kow, the more likely it

is that the chemical dissolves easily in water

and therefore is available to natural

breakdown processes in the environment;

the higher the Kow, the more likely the

chemical is to partition to biological lipids

like fish tissue, where it might concentrate in

biological organisms, or bioconcentrate. If

the test result is a low Kow, or a “ready

biodegradability” test shows that the

chemical rapidly degrades (which means it

is not persistent in the environment), no

further PBT-related testing is required. If the

chemical has a high Kow and does not pass

the ready biodegradability test, the chemical

would proceed on to Tier 2 testing.

■ Tier 2. In this next tier, a more sophisticated

measure of biodegradability is determined

according to a test called the “shake-flask

die-away” test, or an equivalent test. This

test measures how long it takes for the

chemical to disappear by chemically

breaking down. The potential of the

chemical to bioaccumulate (be taken up in

fish by any route, through the gills or the

gut) is determined by experimental

measurement of the bioconcentration factor.

A fish bioconcentration test is the most

convenient way to experimentally measure

bioaccumulation and refers to how well the

chemical concentrates in the fish tissue. If

the measured biodegradation half-life is

greater than 60 days and the measured

bioconcentration factor is high (greater than

l000), the chemical is expected to linger in

the environment (be persistent), and

concentrate in fish tissue. As a result, the

chemical manufacturer is then required to do

Tier 3 testing. If only one condition is met,

releases and exposure are further considered

to determine if additional testing is required.

■ Tier 3. This tier looks at the chemical’s

ultimate fate in the environment and toxicity

to animals up the food chain, i.e., animals that

eat fish, including birds and mammals, and

human beings. Possible toxicity tests include

long-term toxic effects on fish and water

fleas; testing to evaluate effects on other

living creatures, such as birds and organisms

dwelling in the sediment of streams and

lakes; and testing of effects such as potential

for endocrine disruption (potential effects of

synthetic chemicals on the hormone systems

of people and wildlife). Environmental fate

testing determines how the test chemical

interacts with the environment, including

transport and transformation. These kinds of

tests permit scientists to draw more accurate

and reliable conclusions about how the

chemical will act in natural aquatic

environments than is possible with lower tier

test methods, and allow EPA to screen

potentially toxic chemicals prior to entering

commerce that have, in the previous testing

tiers, been confirmed as persistent and

bioaccumulative.

This article describes a process by which

EPA screens new chemicals and decides what

controls should placed on PBT chemicals prior to

their entry into the marketplace. The process is

also applied to other new chemicals, and works

to ensure that chemical companies develop

products that are safer to human health and the

environment.

(continued from previous page)

Defining a PBT

category helps

EPA to gather

additional

information as

needed about

persistence

and bioaccumulation

and tailor

regulatory

requirements

as appropriate

to protect

human health

and the

environment.
Winter 1999 13

Progress of the Great Lakes

Binational Toxics Strategy

Dan Hopkins, EPA Region 5

The Great Lakes Binational Toxics Strategy

(BNS) was signed by the United States and

Canada in April 1997. The process of

implementing the BNS did not begin until

January of 1998. At that time, the U.S. and

Canada, with suggestions from stakeholders,

drafted an implementation plan for the BNS.

The implementation plan called for the

formation of substance-specific workgroups

consisting of environmental organizations, states,

industry, tribes, and governments to address the

challenges set out in the BNS for the Level One

substances. The Level One substances are as

follows: mercury and mercury compounds,

dioxins and furans, polychlorinated biphenyls

(PCBs), hexachlorobenzene and benzo-a-pyrene,

alkyl-lead, octachlorostyrene, and pesticides. The

pesticide work group is specifically addressing

chlordane, aldrin/dieldrin, DDT, mirex, and

toxaphene. To date, there have been two meetings of all BNS stakeholders, a steering group

referred to as the Forum. The purpose of the

Forum is to establish and maintain the

workgroups, assess progress to date under the

Strategy, and exchange information and ideas

leading to further reductions in these substances.

In addition to the substance-specific work

groups, an Integration Workgroup composed of

similar stakeholders has been formed to discuss

cross-cutting issues such as how to address

contaminated sediments and account for longrange transport of the Level One substances.

Discussions about these issues included

providing incentives for stakeholders to

voluntarily undertake reductions which are then

discussed with management officials of EPA

and Environment Canada. The Integration Work

Group met in June 1998 and was scheduled to

meet again in January 1999.

Partnerships among stakeholders are

another important marker of progress in

implementing the BNS. Since the development

of the BNS, several partnerships have formed.

In the U.S., the American Hospital Association

and EPA have signed a Memorandum of

Understanding (MOU) to work together toward

the virtual elimination of mercury from hospital

waste, to provide education, and to develop a

model waste management plan. In another

partnership agreement, three northwest Indiana

steel mills, the Lake Michigan Forum, the

Indiana Department of Environmental

Management, and EPA signed an agreement to

conduct an inventory of mercury in equipment

and wastes, and to develop mercury reduction

plans. The Chlorine Institute, on behalf of its

members, committed to reduce mercury use in

the chlor-alkali industry by 50% from 1990-

1995 levels, aiming for an annual reduction in

mercury usage of 80 tons by the year 2005. Six

Ontario hospitals in Canada signed an MOU for

the voluntary reduction and elimination of

mercury. Several additional hospitals have

indicated an intention to sign this MOU.

A number of other activities related to the

reduction of the BNS Level One substances have

taken place. These activities include the

promulgation of new regulations by EPA,

reductions achieved by Great Lakes stakeholders

resulting from earlier initiatives, and EPA and

state-funded activities such as pesticide

collection programs. In addition to actual

reductions and newly formed partnerships, the

U.S. and Canada have achieved significant

strides to improve source and emission

inventories for the BNS Level One substances,

and to identify opportunities for further

reductions of many of the substances.

The American

Hospital

Association

and EPA have

signed a

Memorandum

of Understanding to

work together

toward the

virtual

elimination of

mercury from

hospital waste.

PBTs
14 Chemicals in Our Community

Update on EPA’s Fish

Contamination Program

Jeff Bigler

State and tribal officials monitor fishing

waters and fish for contaminants and issue health

advisories to the public if fish consumption is

deemed unsafe. EPA’s Fish Contamination

Program (FCP) provides technical assistance to

states, tribes, and others on matters related to

persistent bioaccumulative toxics in fish and

wildlife and associated potential health risks to

consumers. Through this program, EPA

publishes guidance documents; develops and

manages national databases; holds national

forums, conferences and training workshops;

provides grants for advisory development;

conducts special studies; develops outreach

materials; and assists in the issuance of advisories

informing the public about safe amounts of fish

to eat. Since 1992, the FCP has worked closely

with state and tribal agencies to establish a

national consistency in the development and

management of advisories. It helps establish

approaches, methods, and protocols for assessing

contaminants in fish and wildlife.

The FCP has published and revised a fourvolume set of guidance documents titled

Guidance for Assessing Chemical Contaminant

Data for Use in Fish Advisories. Used together,

these four volumes provide an approach for

writing risk-based, scientifically sound, and costeffective advisories. Over the past eight years, the

number of states using this risk-based approach

has increased from 10 to approximately 40. FCP

continues to work with the remaining states to

achieve the goal of national consistency in fish

consumption advisories. This national consistency

goal is an Action Item included in the Clean Water

Action Plan, announced by President Clinton and

Vice President Gore.

In February 1998, the Administration

published the Clean Water Action Plan:

Restoring and Protecting America’s Water,

providing a blueprint for restoring and protecting

the nation’s water resources. A major premise of

the Plan is that informed citizens and officials

can make better decisions with clear, accurate,

and timely information. Beginning in 1993, the

FCP began publishing the National Listing of

Fish and Wildlife Advisories (NLFWA). This

database includes all available information

describing state, tribal, and fish consumption

advisories issued by EPA and other federal

agencies in the United States for the 50 states,

the District of Columbia, and four U.S.

territories. It has been expanded to include the 12

Canadian provinces and territories. The NLFWA

contains information provided to EPA by the

states, tribes, and Canada as of December 1997.

In addition to the development of national

guidance and database management, the FCP

organizes national conferences on chemicals in

the environment, conducts training workshops,

and sponsors the Annual State/Tribal/Federal

Forum on Contaminants in Fish. This Forum is

attended by representatives from all 50 states,

30-40 tribes, several federal agencies, and

various environmental and industry groups. The

next Forum will be held in May 1999.

The FCP is also involved with the conduct

of special studies, which currently includes

studies of subsistence villages in Alaska, the

effectiveness of fish consumption advisories, and

comparative dietary risks. During 1997-98, the

FCP conducted one of the largest site-specific

fish contamination studies ever undertaken by

EPA. Fish, shellfish, and marine plants were

collected from the Cook inlet area of Alaska to

determine if oil and gas activities were affecting

the quality of the food supply. The study will

provide the information needed to characterize

health risks from fish and wildlife harvested

from Cook Inlet by members of four native

Alaskan villages dependent on marine resources

as a source of dietary food items. The study

design, methods, and protocols are based on the

FCP guidance series mentioned earlier in this

article. This human health risk assessment is part

of a larger EPA effort to characterize human

health risks from pollutants associated with

offshore and coastal oil and gas Industry practices.

EPA will issue a final report in the Spring of 1999.

The FCP is working with EPA’s Office of

Research and Development (ORD) and the State

(continued on next page)

During 1997-98,

the FCP

conducted one

of the largest

site-specific fish

contamination

studies ever

undertaken by

EPA.

PBTs
Winter 1999 15

of Wisconsin on a second study, to assess the

awareness about and effectiveness of the

advisories. The study, which is national in scope,

will use focus group techniques to interview

women of childbearing age in states issuing

mercury advisories to determine:

• their fish consumption habits;

• the channels by which they receive health

information;

• how they prefer to receive advisory

information;

• how they perceive health risk due to

consumption of sport fish; and

• what they view as the central risk message

that needs to be communicated.

The study will lead to a protocol which

states and tribes may use for effectively

communicating targeted mercury fish

consumption advisories to women and children.

Based on the focus groups, EPA will determine

how to distribute intervention materials, design

an intervention tool (advisory), and then

determine if the tool is effective in lowering this

sub-population’s fish consumption habits and/or

mercury body burden levels. A draft report is

expected in 1999.

The third special study, Comparative Dietary

Risk, involves the collection and assessment of

data concerning health risks and benefits of

behavior changes due to fish consumption

advisories. This study will provide a

comprehensive document on what is known

about health risks from consumption of

contaminated fish, health risks from lack of fish

consumption, health benefits of consuming fish,

general problems associated with comparisons of

these risks, and a proposed approach to evaluate

the risks and benefits of fish consumption and

other dietary food items. This research should

lead to a better understanding of the impacts that

fish consumption advisories could have on an

individual’s diet. Local risk managers and

ultimately individual consumers could evaluate a

broad range of dietary information before

making decisions about whether to consume fish

from contaminated areas. Furthermore, states and

tribes may use the results to assess local

populations and conditions and tailor fish

consumption advisories to better reflect the local

conditions. EPA will hold a workshop of national

and international experts during the Winter of

1998/1999 to develop the final draft document.

Prior to completing the document, EPA will ask

the Science Advisory Board or another peer

review group to comment on the approaches and

methods included in the document.

The FCP is also involved with the

development and dissemination of outreach

materials. In collaboration with the

ATSDR, the FCP will be writing to

health care professionals nationwide to

emphasize the need to be aware, and to

ensure the public is aware, of the

possible health consequences to those

who consume contaminated

noncommercial fish (i.e., fish caught

through sport or subsistence fishing).

This effort is also part of the

President’s Clean Water Action Plan.

This Plan provides a blueprint for a

new cooperative approach to identify

and solve pollution problems and to

inform citizens and officials about the

quality of water bodies, and the safety

of the fish and drinking water that come from

them, as well as the beaches that surround them.

Attached to the letters to health care providers

will be copies of the brochure, Should I Eat the

Fish I Catch?, developed by ATSDR and the

FCP to provide information to consumers about

how to reduce health risks from eating fish

containing chemical pollutants. It is part of the

Action Plan and is available in three languages

(English, Spanish, and Hmong).

Lastly, the FCP assists in the issuance of

individual advisories to ensure adequate

protection of public health. In 1997, the FCP, in

collaboration with ATSDR, coordinated the

development and issuance of the first federal fish

consumption advisory. The State of Michigan

was prepared to issue an advisory which EPA

determined did not provide adequate protection

of public health, particularly for women and

children. EPA printed and distributed a total of

1.2 million copies of the federal advisory to

fishing license holders and health care facilities

throughout the State of Michigan. In 1998,

Michigan issued a new advisory providing

adequate protection of women and children. The

FCP continues to work with other states to

ensure advisories are issued that are protective of

public health.

(continued from previous page)

For more information

concerning the National

Fish Contamination

Program or for copies of

the above described

materials, contact Jeffrey

Bigler, National Program

Coordinator, phone:

202-260-1305,

fax 202-260-9830,

e-mail: bigler.jeff@

epamail.epa.gov;

or write to:

U.S. EPA (4305), Fish

Contamination Program,

401 M Street SW,

Washington, DC 20460.
16 Chemicals in Our Community

Mercury, a naturally occurring metal, moves

between the water, the air, and soil as a result of

natural and human activities. It enters the

environment from sources like coal-fired power

plants, mining and smelting of various ores, and

the disposal of consumer products manufactured

with mercury. Because it is a persistent,

bioaccumulative and toxic (PBT) pollutant, the

amount of mercury in the biosphere has been

increasing since the beginning of the industrial

age. In its organic form, methylmercury

bioaccumulates in fish and becomes more

concentrated as it moves up the food chain to

humans and other animals who eat the fish.

Mercury is the most frequent reason for fish

consumption advisories in the U.S., accounting

for 60 percent of all advisories in fresh water

bodies. To date, 40 states have issued advisories

for mercury in one or more water bodies, and 11

states have issued them on a state-wide basis.

Mercury is a well-known and longestablished neurotoxin that slows fetal and child

development and causes irreversible deficits in

brain function. Scientific debate is ongoing to

more precisely determine the level of mercury

exposure at which effects begin to occur.

Several, but not all, existing studies show

adverse human health effects at the level at

which many Americans are exposed today from

fish consumption. Tens of thousands of babies

are born each year after being exposed in the

womb to levels of mercury at which some

studies have shown adverse health effects.

The draft EPA Action Plan for Mercury is

the first of a series of such national action plans.

It is a part of EPA’s draft Multimedia Strategy for

Priority Persistent, Bioaccumulative, and Toxic

(PBT) Pollutants. The Agency has reviewed

current regulations, initiatives, and programs

which manage and control mercury, and has

identified a set of cost-effective options to move

toward achieving further reductions.

Specifically, EPA proposes the following

actions, in consultation with other federal

agencies, and with the involvement of states,

tribes and other stakeholders.

• Control emissions from air point sources.

• Revise the water quality criterion, and

improve measurement of mercury in water.

• Seek reductions in uses of mercury and

improve information and citizens’ right-toknow.

• Develop an environmentally acceptable

disposal method for mercury wastes

designated as hazardous wastes.

• Seek reduction in exposure to highly

exposed populations.

• Decrease further environmental

contamination from illegal use/disposal of

mercury through focused compliance

monitoring and enforcement of mercury

restrictions and requirements.

• Continue international efforts to reduce

mercury releases.

• Perform and support further research on all

aspects of the mercury problem.

• Support regional, state, tribal, and local

actions to reduce mercury.

For copies of the draft EPA Action Plan for

Mercury and other related documents, contact

the Pollution Prevention Information

Clearinghouse at (202) 260-1023 or access the

EPA Web site at www.epa.gov/pbt/strategy.htm.

EPA’s Draft Action Plan for Mercury

Karen Maher

The amount

of mercury in

the biosphere

has been

increasing

since the

beginning of

the industrial

age.

PBTs
Winter 1999 17

Preparing the Mercury Research Strategy

Kathryn Mahaffey and Jonathan Herrmann

According to the December 1997 Mercury

Study Report to Congress, the total annual global

input of mercury to the atmosphere from all

natural sources and human activity is 5,500 tons.

Approximately 150 tons of that amount is

emitted by human activity within the United

States. Mercury is released into the environment

as either an element (e.g., the silvery metal

released as a liquid or vapor) or as one of a

number of compounds (e.g., mercuric chloride).

Depending on a number of factors, including the

type of mercury released, its transport/deposition

pattern can result in either:

• Local scale impacts (e.g., depositing within

30 miles of an emissions source);

• Regional scale impacts (e.g., depositing

thousands of miles from a source over a

wide area); or

• Global scale impacts, i.e., becoming part of

the global emissions pool, where it can

remain for a year before depositing on either

land or water.

Deposited mercury, particularly when it

resides in lake sediments, transforms to methyl

mercury, an organic form of mercury, which is

eventually taken up in fish. Such mercury can

then accumulate in the tissues of both humans

and wildlife (e.g., eagles, otters) if they eat

mercury-containing fish. Numerous water bodies

in the United States have fish advisories for

mercury. There are also mercury “all coastal

waters” advisories for those states bordering the

Gulf of Mexico.

In response to this situation, EPA’s Office

of Research and Development is preparing a

Mercury Research Strategy with the help of

scientists and engineers from other EPA

program offices and regions. The strategy will

provide a framework

to address unanswered

research questions on

the assessment and

management of

mercury releases from

human activities and

natural sources. The

Mercury Research Strategy will

consider a number of issues related to the

following set of research themes:

• Hazards of methyl mercury to human health;

• Ecological effects of mercury/methyl

mercury;

• Modeling and monitoring of environmental

media for mercury;

• Human and wildlife exposures to methyl

mercury through the aquatic foodweb;

• Control technologies for combustion sources

of mercury;

• Controls for non-combustion sources of

mercury; and

• Risk communications on mercury/methyl

mercury;

EPA is currently rewriting the strategy

following an internal review this past Fall. It is

scheduled to undergo external peer review in the

Spring of 1999. Once the strategy has undergone

this review, ORD and EPA offices, in

cooperation with the greater scientific

community, will develop and implement the EPA

research plan. The plan will build on ongoing

efforts on the research themes listed above and

will support EPA’s regulatory and court-ordered

deadlines for mercury.

Numerous

water bodies

in the United

States have

fish advisories

for mercury.

PBTs
United States

Environmental Protection Agency(7407)Washington, DC 20460Official BusinessPenalty for Private Use$300Address Service Requested

First Class Mail

Postage & Fees Paid

EPA

Permit No. G-35